original paper oxide minerals in the granitic cupola …salamanca, spain. part ii: sn, w and ti...

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Journal of Geosciences 57 (2012) 155ndash171 DOI 103190jgeosci119

Original paper

Oxide minerals in the granitic cupola of the Jaacutelama Batholith Salamanca Spain Part II Sn W and Ti minerals in intra-granitic quartz veins

Teresa LLORENS Mariacutea Candelas MORO

Department of Geology University of Salamanca Plaza de los Caiacutedos sn 37006 Salamanca Spain tllgusales Corresponding author

The mineralized quartz veins hosted by the distal granitic facies of the Jaacutelama Batholith were generated by successive processes of the fractures opening and filling by hydrothermal fluids enriched in volatiles Cassiterite I wolframite I and rutile I crystallized during an early stage followed ndash after a ductile deformation ndash by a main FendashZn sulphide deposition composed initially by subordinate cassiterite II and wolframite II Later during this main sulphide deposition ixiolite and NbndashTa-rich rutile II filled fractures Finally the late open spaces and cavities were sealed by quartz and carbonates The crystallization of wolframite II indicates enrichment in Mn of the fluid compared with wolframite I suggesting a normal evolutionary trend from the early SnndashW deposition to the first stage of the main FendashZn sulphide precipitation in the quartz veins The scarcity of Sn during the latest stages of the ore deposition prevented the crystallization of cassiterite favoring instead the incorporation of this element into the ixiolite and rutile II structure This hydrothermal evolution from the crystallization of wolframite II to ixiolite and rutile II responded to enrichment in Ti and Fe of the late fluid thus favoring a partially reversed trend in the NbndashTandashTi oxides composition The late enrichment in Ti and Fe of the hydrothermal fluid could be explained by contamination by external metamorphic andor meteoric fluids en-riched in these elements The incorporation of Ti Nb and Ta into the ixiolite and rutile structure was favored by high F concentrations in the hydrothermal fluids inherited from the residual melts of the Jaacutelama Batholith

Keywords Jaacutelama Batholith quartz veins cassiterite wolframite rutile ixioliteReceived 7 February 2012 accepted 21 August 2012 handling editor M Novaacutek

1 Introduction

Cassiterite and wolframite represent the most common Sn and W minerals related to S-type granites and thus have been studied extensively (eg Černyacute et al 1985 Gouanvic and Babkine 1985 Giuliani 1987 Černyacute and Ercit 1989 Neiva 1996 2008 Haapala 1997 Lerouge et al 2007 Pal et al 2007) Additionally NbndashTa oxide minerals containing variable amounts of W are com-mon in this type of rare-metal granites and related granitic pegmatites (eg Černyacute and Ercit 1985 1989 and references therein Johan and Johan 1994 Tindle et al 1998 Černyacute and Chapman 2001 Auriscchio et al 2002 Breiter et al 2007 Černyacute et al 2007a Beurlen et al 2008 Novaacutek et al 2008 Martins et al 2011 Reneacute and Škoda 2011) These pegmatite bodies generally belong to the LCT family of Černyacute and Ercit (2005) In contrast much less attention has been paid to the NbndashTa oxide minerals in hydrothermal quartz veins with cassiterite andor wolframite (Amichba and Dubakina 1974 Beddoe-Stephens and Fortey 1981 Tindle and Webb 1989 Neiva 1996)

The Jaacutelama Batholith in the Navasfriacuteas District in the central part of the Iberian Massif (Fig 1) is a great example

having a representation of all these mineralization types It has been well known for decades for its peri-batholithic pegmatite dikes and intra-granitic quartz veins that were mined for cassiterite andor wolframite (Fernaacutendez-Leyva 2007 Llorens 2011) The mining district is formed by the Cadalso-Casillas de Flores Batholith and the Jaacutelama Batholith granitic cupola Recent contributions showed the broad mineralogical and chemical variability of these deposits which is not restricted to the Sn and W ores For example abundant Fe- Mn- Sr- Li- Ca- and Mg-bearing phosphates have been documented from the granites the pegmatite dikes and the mineralized quartz veins (Llorens and Moro 2007 2008 2012a Moro and Llorens 2008) These phosphates have been useful for determining the magmatic hydrothermal and supergene evolution of the Jaacutelama Batholith Additionally the granitic pegmatites host important amounts of columbite- and pyrochlore-group minerals (Llorens and Moro 2010a b c) whereas rutile enriched in Nb and Ta and ixiolite with high W and Ti con-tents have been identified in the mineralized quartz veins

This contribution aims to complement the character-ization of the SnndashWndashNbndashTandashTi mineralization related to the Jaacutelama Batholith which was introduced in Part I (Llorens and Moro 2012b) with a study of the granitic

Teresa Llorens Mariacutea Candelas Moro

156

facies and the pegmatite dikes Thus the main objectives are 1) to identify the different episodes of mineralization in the quartz veins 2) to characterize texturally miner-alogically and chemically SnndashWndashNbndashTandashTi minerals of each episode 3) to describe the substitution mechanisms and zoning patterns of these minerals 4) to define the chemical evolution of the SnndashWndashNbndashTandashTi minerals in the quartz veins through their textural relationships and compositional variations and finally 5) to determine the role of volatiles in the formation of this deposit

2 Geological setting

The Jaacutelama Batholith intruded the pre-Ordovician grey-wackendashpelite metasediments of the Schist-Greywacke Complex Domain (CEG) in the middlendashwestern Iberian Peninsula (Martiacutenez Catalaacuten et al 2004) after the main Variscan deformational phases (~300 Ma Ramiacuterez 1996) The External Unit of the Jaacutelama Batholith (Ramiacuterez 1996 Ramiacuterez and Grundvig 2000) hosts the main tinndashtungsten deposits of the Navasfriacuteas district (geographic coordinates

CadalsondashCasillasMassif


Jaacutelama

Batholith

Jaacutelama

Batholith

Guarda Batholith

Spain

0 3 km

Salmantina Group

External Unit

Salamanca

Tertiary

Granites

Paleozoic

Gradual contact Intrusive contact

Fractures Qtz veins directions

Tourmaline-bearing leucogranite

Apical aplitesTwo-mica granite

SchistndashGraywacke Complex (CEG)Porphyritic monzogranite

CEG

Horia amp Mari Carmen

Bon

N

Iberian Massif

0 20 km

SnndashW deposit

Portugal Spain

Sn depositSn depositNavasfriacuteasNavasfriacuteas

SnndashW deposit

3 km

Fig 1 Location of the Jaacutelama Batholith in the Navasfriacuteas SnndashW district (central part of the Iberian Massif) The principal directions of the mine-ralized quartz veins that were mined can be seen Based on Ramiacuterez (1996)

Sn W and Ti minerals in the quartz veins of the Jaacutelama Batholith Spain

157

40265708 -679616) in both peri-batholithic pegmatite dikes and in intra-granitic quartz veins The latter are much more abundant in the tourmaline-bearing leucogranite and the apical aplites than in the two-mica equigranular granite (Fig 1) Two groups of quartz veins can be distinguished within the Jaacutelama Batholith depending on the host rock

(1) Sn-bearing quartz veins are hosted by the two-mica equigranular granite of the Horia and Mari Carmen mines These subvertical veins of tabular or lenticular shape are up to several decimeters thick (Fig 2a) and are striking mainly N170ordmEndashN180ordmE In some cases the intrusion of these mineralized quartz veins induced a selvage zone c2 cm thick composed of quartz and muscovite along the contact with the granitic host rock (Fig 2a) The ore minerals generally crystallized both in the centers of the quartz veins where they are normally related to fractures and in the outermost zones forming massive and fine-grained crystalline aggregates

(2) SnndashW mineralization of the Salmantina Group and Bon mines occurs in swarms of quartz veins hosted by the tourmaline-bearing leucogranite and border ap-lites These subvertical veins strike predominantly from N70ordmE to N110ordmE which matches most of the old min-ing works (Fig 1) as well as constitutes the main late-Variscan fracture system The subvertical veins striking N40ordmE and N60ordmE are less common In general all these quartz veins display mainly lenticular shapes and vary

from several centimeters to decimeters in thickness (Fig 2b) In some cases they are arranged en echelon indicating that they were formed as a consequence of extensional movements or fractures (Bons 2000) Thus the direction of these quartz veins changes continuously leading in places to a development of structures such as stockworks In these cases the veins are usually less than 10 cm thick

The mineralized quartz veins contain the most impor-tant amounts of cassiterite and wolframite with more than 600 ppm Sn and 1000 ppm W on average Addition-ally sulphides such as arsenopyrite and sphalerite are abundant together with variable and accessory amounts of pyrite pyrrhotite chalcopyrite stannite BindashPbndashAg sulphosalts and gold (Moro et al 2001) Finally the quartz veins striking preferentially from N90ordmE to 100ordmE contain an interesting phosphate assemblage This con-sists mainly of triplite and its alteration products such as isokite bermanite phosphosiderite and fluorapatite (Moro and Llorens 2008 Llorens and Moro 2012a)

3 Analytical techniques

A total of 125 samples of the mineralized intra-granitic quartz veins were collected in situ from several zones of the Navasfriacuteas district (Fig 1) Forty of them

Fig 2a ndash Outcrop of the mineralized quartz veins hosted by the two-mica equigranular granite They strike N180degE with subvertical dip and have muscovite-rich selvages b ndash Crossing of N90degE and N65degE striking veins hosted by the tourmaline-bearing leucogranite of Salmantina Group


158

containing Sn W and Ti minerals were selected for chemical analyses A total of 33 electron-microprobe analyses (EMPA) of cassiterite 13 of ferberite 20 of huumlbnerite 10 of ixiolite 45 of NbndashTa-rich rutile and 7 of rutile have been carried out The minute size of rutile and ixiolite hindered their separation such that the use of X-ray diffraction techniques was not pos-sible Accordingly their identification was carried out by combined light and electron microscopy for the petrographic and mineralogical study and was also based on their chemical composition We employed a Cameca SX-100 electron-microprobe at the Scientific-Technical Services of the University of Oviedo which was operated with an accelerating voltage of 20 kV and a sample current of 20 nA The counting time was 20 s for Zr W Fe Ta and Al and 10 s for the rest of elements The detection limits and standard deviations range between 001 and 004 wt and between plusmn002 to plusmn010 respectively for major and up to 011 wt and between plusmn012 to plusmn034 respectively for trace ele-ments The following standards were used metals for Ti Sn W and Zr vanadinite for V magnetite for Fe MnTiO3 for Mn Ta2O5 for Ta Nb2O5 for Nb andradite for Ca and corundum for Al Back-scattered electron images and semi-quantitative analyses were obtained using the electron-microprobe at the Scientific-Techni-cal Services of the University of Oviedo and the SEM at the University of Salamanca (ZEISS DSM 940) to determine the compositional variations and zoning of the Sn W and Ti minerals

4 Mineralogy and chemistry of the Sn W and Ti phases

The formation of the mineralized quartz veins of the Jaacutelama Batholith resulted from a complex polyphase process that involved the injection of different fluids into the same structure (Fig 3) (Llorens 2011)

At the first step an early SnndashW deposit developed with subordinate rutile and sulphides After a ductile deforma-tion the main ore was deposited An intense fracturing divided this step into two subphases The first was repre-sented by the crystallization mainly of FendashZn sulphides and less SnndashW minerals During the second one abundant FendashCu sulphides and BindashPbndashAg sulphosalts crystallized together with accessory ixiolite and a second generation of rutile The final step consisted of a late filling mainly composed of quartz and locally carbonates

Among the different SnndashWndashNbndashTandashTi deposits of the Navasfriacuteas district the most important minerals mined in the northern part of the Jaacutelama Batholith were cassiterite and wolframite hosted by the intra-granitic quartz veins of the Horia Mari Carmen Salmantina Group and Bon mines Although subordinately Ta- and Nb-rich rutile and ixiolite were identified exclusively in the quartz veins of the Salmantina Group

41 Cassiterite

Cassiterite is the main ore mineral occurring in the quartz veins of the Jaacutelama Batholith both in their core parts and less commonly in the selvage zones Cas-siterite appears as micrometer- to centimeter-sized (up to 2 cm long) subhedral to euhedral crystals as well as anhedral aggregates of more than 5 cm across In both cases simple and polysynthetic twins are more com-mon than elbow twins Under the optical microscope the crystals of cassiterite usually show a distinct zon-ing owing to the alternation of intensely red and paler bands However this optical zoning does not respond to any particular chemical variation pattern Considering the paragenetic relationships two episodes of cassiterite deposition were identified (Fig 3) cassiterite I which is related to the early SnndashW precipitation (Fig 4a) and cassiterite II which crystallized at the beginning of the main FendashZn sulphides deposition (Fig 4b) Rounded

Fig 3 Schematic mineral sequence of the SnndashW quartz veins hosted by the granitic facies of the Jaacutelama Batholith

FendashCu sulphides

Cassiterite

Wolframite

Rutile

BindashPbndashAg sulphosalts

FendashZn sulphides

Ixiolite

Early SnndashW ore Main sulphide deposit Late deposit

ductile deformation fracturing


159

rutile I crystals up to 15 microm are commonly included in cassiterite II

There are no chemical differences between the two cassiterite generations They show a composition close to the ideal (SnO2) in which the cationic site is occupied by Sn (0977ndash0993 apfu) and significant contents of Ti (up to 0012 apfu TiO2) (Tab 1) The Ti contents are signifi-cantly higher than those found in the cassiterite hosted by pegmatite dikes of the Jaacutelama Batholith (Llorens and Moro 2012b) Moreover Fe Nb and W may be present in the crystal structure of cassiterite as trace elements Tungsten is generally related to the presence of wolfram-ite in the quartz veins hosted by the tourmaline-bearing leucogranite and apical aplites

42 Wolframite

Wolframite occurs exclusively in swarms of quartz veins striking from N70ordmE to N110ordmE which are hosted by the tourmaline-bearing leucogranite and the border aplites It crystallized especially within the outermost zones of

the veins and may be associated with cassiterite crystals Wolframite appears as single prismatic crystals forming millimeter-to-centimeter sized crystalline aggregates perpendicular to the walls of the quartz veins (Fig 4c) As in the case of cassiterite two episodes of wolframite growth were identified based on the textural and com-positional features Wolframite I crystallized during the early stages of mineralization together with cassiterite I Its composition is predominantly ferberitic being locally enriched in Mn in some veins Wolframite II was formed during the first episode of the main ore deposition associ-ated with cassiterite II and is dominated by a huumlbneritic component In many cases crystals of wolframite I (fer-berite) were partially dissolved and recrystallized later as wolframite II (huumlbnerite) (Fig 4d)

The average ferberite composition corresponds to the formula (Fe061Mn036)Σ097WO4 where W has been substi-tuted by up to 0024 apfu Zr and traces of Nb (up to 0011 apfu) (Tab 2) The contents of Fe3+ calculated by charge balance for two cations (Ercit et al 1992) are always less than 0020 apfu A strong enrichment in Fe is notewor-

Fig 4a ndash Fragment of a mineralized quartz vein of the Salmantina Group with cassiterite I (Cst I) wolframite I (Wf I) and arsenopyrite (Apy) together with triplite (Tp) and apatite (Ap) b ndash Microscopic image of zoned cassiterite II (Cst II) aggregates with arsenopyrite (plain transmitted light) c ndash Subhedral crystals of wolframite II (Wf II) and arsenopyrite aggregates in a quartz vein (Qtz) d ndash BSE image of wolframite I with a patchy zoning as a consequence of replacement by wolframite II


160

thy in the wolframite I crystallized in one of the mines located in the apical parts of the Jaacutelama granitic cupola (Bon mine Fig 1) As mentioned above only wolframite I crystallized in a sample of the quartz veins (Salmantina Group mine) shows a huumlbneritic composition despite be-longing to the same mineralization event The mean for-mula of this huumlbnerite I is (Fe041Mn058)Σ1WO4 whereby Nb substitutes for up to 0011 apfu of W In contrast sev-eral crystals of wolframite II (huumlbnerite) contain higher amounts of Fe3+ than the earlier ferberite (up to 0090 apfu) with an average formula (Fe037Mn061)Σ098WO4 (Tab 2)

43 Ixiolite

Ixiolite was only identified in the quartz veins hosted by the tourmaline-bearing leucogranite and the border aplites of the Salmantina Group It occurs as acicular crystals or anhedral aggregates that fill holes and frac-tures together with rutile II preferentially associated with sulphides (Fig 5andashb) According to the textural features ixiolite crystallized slightly earlier than rutile II as the latter mineral coated several crystals of the former (Fig 5a) Ixiolite commonly shows a zoned tex-

ture owing to slight variations in its Nb Ta Ti and W contents (Fig 5b) It has a rutile-type general formula (TaNbSnFeMn)O2 containing high Nb (between 0240 and 0450 apfu) Ta (between 0073 and 0357 apfu) W (up to 0111 apfu) and Ti (up to 0139 apfu) and only traces of Sn (up to 002 apfu) A significant enrichment in Fe (up to 0272 apfu) and minor in Mn (up to 0130 apfu) was noted (Tab 3)

44 Rutile

Two types of rutile were identified texturally and chemi-cally in the mineralized quartz veins Rutile I crystal-lized preferentially in the quartz veins hosted by the two-mica equigranular granite of the Horia and Mari Carmen mines (Fig 1) It occurs as micrometer-sized anhedral crystals included in the colorless zones of cas-siterite I Its chemical composition is dominated by Ti which occupies most of the cationic site varying from 0890 to 0946 apfu Titanium is partially substituted

Tab 1 Representative compositions of cassiterite (wt and apfu)

Vein host Equigranular granite LeucograniteaplitesSample 1711 1775B 1691 1785BAnalysis 33 17 65 21WO3 000 000 007 004Nb2O5 017 000 024 042Ta2O5 000 000 000 000TiO2 048 073 060 003ZrO2 000 000 000 000SnO2 9857 9900 9883 9905Al2O3 000 000 000 000V2O3 bdl bdl 000 bdlMnO 004 002 000 000FeO 007 000 009 018Total 9935 9979 9983 9972W 0000 0000 0000 0000Nb 0002 0000 0002 0004Ta 0000 0000 0000 0000Ti 0008 0012 0010 0001Zr 0000 0000 0000 0000Sn 0988 0987 0985 0992Al 0000 0000 0000 0000V 0000 0000 0000 0000Mn 0001 0000 0000 0000Fe 0001 0000 0002 0003sumcat 1 000 1 000 1 000 1 000Mn(Mn+Fe) 0375 0943 0011 0000Ta(Ta+Nb) 0000 0000 0000 0000

Ndeg of ions (in apfu) calculated on the basis of 2O bdl below de-tection limit

Tab 2 Representative compositions of wolframite (wt and apfu)

Vein host LeucogranitesaplitesMineral Wf I Wf I Wf I Wf II Wf II Wf IIAnalysis 11 22 52 11 23 62WO3 7578 7553 7490 7636 7460 7614Nb2O5 017 033 033 026 047 025Ta2O5 000 007 000 000 bdl 000TiO2 006 bdl bdl 002 008 003ZrO2 082 090 089 070 073 086SnO2 000 002 003 bdl 006 000Al2O3 000 000 000 000 000 000V2O3 000 000 000 bdl 000 000CaO bdl bdl 003 bdl 002 002MnO 971 1338 198 1429 1341 1609FeO 1342 998 2150 908 1011 678Total 9995 10023 9967 10075 9949 10016W 0992 0981 0978 0990 0971 0996Nb 0004 0008 0008 0006 0011 0006Ta 0000 0001 0000 0000 0000 0000Ti 0001 00004 0000 0001 0003 0001Zr 0020 0022 0022 0017 0018 0021Sn 0000 0001 0001 0000 0001 0000Al 0000 0000 0000 0000 0000 0000V 0000 0000 0000 0001 0000 0000Ca 0001 0001 0002 0001 0001 0001Mn 0415 0568 0085 0605 0570 0688Fe2+ 0567 0418 0880 0380 0380 0286Fe3+ 0000 0000 0020 0000 0040 0000sumcat 2 000 2 000 1 994 2 000 1 995 2 000Mn(Mn+Fe) 0423 0576 0086 0615 0573 0706Ta(Ta+Nb) 0016 0106 0000 0000 0010 0000

Ndeg of ions (in apfu) calculated on the basis of 4O bdl below de-tection limit Calculated by charge balance (Ercit et al 1992)


161

contain high quantities of Al2O3 reaching 133 wt (Tab 3)

Rutile II crystallized in the quartz veins hosted by the tourmaline-bearing leucogranite and the border aplites of the Salmantina Group as micrometer-to-

by variable amounts of Nb Ta Fe and Sn although Sn contents are in some cases increased as a consequence of contamination from the host cassiterite As occurs in various intra-granitic pegmatite dikes of the Jaacutelama Batholith several rutile I crystals of the quartz veins

Fig 5 BSE images of the late Nb Ta Ti and W oxides of the mineralized quartz veins a ndash Rutile II (Rt II) aggregates surrounding ixiolite (Ixl) crystals b ndash Oscillatory zoning of the subhedral to euhedral crystals of ixiolite reflecting variations in the Nb Ta Ti and W contents c ndash Aggre-gates of zoned euhedral crystals of rutile II with higher Ti contents in the inner zones (dark grey) and higher Ta contents towards the rims (light grey) d ndash Aggregates of rutile II filling cavities in arsenopyrite (Apy) e ndash Aggregates of rutile II crystals hosted by quartz showing oscillatory zoning in the outermost zones and patchy zoning in the inner ones the latter as a consequence of the presence of exsolution lamellae containing variable amounts of Nb and Ta f ndash Rutile II crystals with partially dissolved rims which have been recrystallized incorporating high Ta contents and containing cassiterite inclusions (Cst)


162

millimeter subhedral to euhedral crystals (Fig 5c) In some cases rutile II with ixiolite filled interstitial spaces forming anhedral aggregates of small euhedral to subhedral grains (Fig 5d) According to Carruzzo et al (2006) such growth might have been caused by the crystallization of rutile II from several randomly ori-ented nuclei which eventually would have amalgam-ated into larger grains if there was no interaction with other crystals that could have stopped their growth Under the optical microscope rutile II shows a more or less regular oscillatory zoning and in some cases a patchy zoning (Fig 5cndashe) generally owing to varia-tions in the Ti content (ranging from 0675 apfu in the lighter zones to 0980 apfu in the darker ones) Nio-bium and tantalum replace Ti in similar proportions up to 0119 apfu each (Tab 3) The borders of the crystals are generally enriched in Nb W and especially in Ta partial dissolution and recrystallization textures are common (Fig 5f) The WO3 contents are less than 300 wt whereas SnO2 contents remain more or less invariable in all samples reaching 250 wt Rutile II shows low Mn and Fe2+ concentrations Most of rutile II crystals show c 020ndash030 wt Al2O3 However

several grains contain higher amounts of Al reaching 334 wt Al2O3 Relatively high ZrO2 contents are noteworthy in all samples of rutile II varying from 099 to 198 wt (Tab 3)

5 Discussion

Commonly a combination of changes in the PndashTndashX conditions of the granitic host rock with the chemical disequilibrium of fluids are usually invoked to explain the compositional variations responsible for example for primary zoning of minerals (Carruzzo et al 2006) Thus the stability of cassiterite and the columbite group minerals in highly differentiated rocks would have been induced by different factors controlling variations of the major components of these minerals (eg Sn Nb Ta Fe and Mn) in the fluid such as falling temperature chang-ing oxygen fugacity activities variations equilibriumndashdisequilibrium with the fluid phase or any combination of the above However these elements together with W and Zr represent trace components which would have replaced Ti in the rutile composition

Tab 3 Representative compositions of ixiolite and rutile (wt and apfu)

Vein host Leucograniteaplites Equigranular grtMineral Ixl Ixl Ixl Ixl Rt II Rt II Rt II Rt II Rt II Rt I Rt IAnalysis 32 51 53 54 1B6 1B7 21 33a 43 17 12WO3 982 1699 420 1700 679 050 011 ndash 127 020 023Nb2O5 3830 4041 2207 3128 748 1427 804 728 137 610 160Ta2O5 2282 2003 5468 3123 247 861 2165 1112 124 358 122TiO2 882 267 296 281 7548 6844 6235 7443 9153 8411 8963ZrO2 000 015 000 bdl 170 137 118 156 182 000 011SnO2 099 067 075 068 093 117 078 033 073 225 197Al2O3 bdl 021 bdl 000 091 bdl bdl 334 bdl 011 133V2O3 bdl ndash ndash ndash ndash ndash ndash ndash ndash 069 044CaO bdl bdl 000 000 000 0028 000 bdl 000 bdl 013MnO 425 620 325 361 000 003 002 000 000 005 bdlFeO 1298 1245 1176 1317 434 548 560 230 208 312 175Total 9804 9981 9967 9987 10010 9996 9980 10042 10011 10032 9841W 0053 0095 0026 0099 0026 0002 0000 ndash 0005 0001 0001Nb 0364 0393 0240 0319 0050 0098 0059 0050 0009 0039 0010Ta 0130 0117 0358 0191 0010 0036 0095 0046 0005 0014 0005Ti 0139 0043 0054 0048 0842 0782 0758 0843 0954 0891 0946Zr 0000 0002 0000 0001 0012 0010 0009 0011 0012 0000 0001Sn 0009 0006 0008 0007 0006 0008 0006 0002 0004 0014 0012Al 0000 0005 0000 0000 0016 0001 0001 0059 0001 0002 0022V 0000 ndash ndash ndash ndash ndash ndash ndash ndash 0006 0004Ca 0001 0001 0000 0000 0000 0000 0000 0001 0000 0001 0002Mn 0076 0113 0066 0069 0000 0000 0000 0000 0000 0001 0000Fe 0228 0224 0237 0248 0054 0070 0076 0029 0024 0037 0020sumcat 1 006 0999 0991 0981 1 011 1 008 1 004 1 040 1 013 1 006 1 023Mn(Mn+Fe) 0249 0335 0219 0217 0000 0005 0004 0000 0000 0015 0004Ta(Ta+Nb) 0264 0230 0598 0375 0166 0266 0618 0479 0352 0261 0314

Ndeg of ions (in apfu) calculated on the basis of 2OIxl ixiolite Rt rutile bdl below detection limit ndash not detected


163

51 Zoning patterns and substitution mechanisms

511 Cassiterite

Generally much of Nb Ta and Fe present in cassiterite analyses should be attributed to submicroscopic inclu-sions and exsolutions impossible to be detected by EMPA However the (Ta + Nb)(Fe + Mn) ratios in all the cassiterite crystals are less than 2 indicating that the Nb content is not exclusively controlled by the inclusions and exsolved blebs of columbite-group minerals (Moumlller et al 1988 Neiva 1996)

Thus the (Nb + Ta) versus the (Fe + Mn) plot for cassiterite from the intra-granitic quartz veins (Fig 6a) shows a roughly 21 positive correlation This suggests a significant role of the ideal (FeMn)2+ + 2(NbTa)5+ harr3(SnTi)4+ substitution to explain the incorporation of Nb and Ta in the cassiterite crystal lattice (Černyacute et al 1985) The high Ti contents most of the cassiterite crys-tals of these quartz veins could furthermore indicate a certain influence of the Sn4+ harr Ti4+ isovalent substitution (Spilde and Shearer 1992)

512 Wolframite

Niobium commonly substitutes for W in many crystals of wolframite both primary and secondary as seen in Fig 6b where Nb correlates negatively with W Al-though in general the Nb concentration in wolframite does not seem to depend on the huumlbneritic component of the crystals those richer in Mn (wolframite II) incor-porate most Nb The strong negative correlation shown in Fig 6c suggests that Nb entered the wolframite structure in solid solution probably by means of the [(FeMn)2+W6+] harr (Fe3+ Nb5+) coupled substitution (Polya 1988 Neiva 2008) This substitution mechanism has been documented in other W-bearing deposits such as at Panasqueira or Vale das Gatas Portugal (Neiva 2008) The fact that both cassiterite and wolframite that crystallized in the quartz veins of the Jaacutelama Batholith contain similar Nb concentrations (up to 046 wt Nb2O5 in cassiterite) suggests that both minerals were formed contemporaneously as also suggested by tex-tural evidence

Furthermore the Fe3+ contents in huumlbnerite which crystallized during the main ore-forming episode (Fig 3) are significantly higher than those observed in earlier ferberite This suggests a slight increase in fO2 and hence the evolution of the fluids towards more oxidizing conditions favoring the incorpora-tion of Nb into wolframite (Tindle and Webb 1989) Huumlbnerite crystallized during the first subphase of the main mineralization in which the wolframite II

and the cassiterite II were associated with FendashZn sul-phides the most abundant minerals in the quartz veins at that stage Accordingly the enrichment in both Mn and Nb in huumlbnerite seems to have been controlled by decreasing temperatures and the fact that the Fe of the mineralized fluid was preferentially incorporated into sulphides such as arsenopyrite pyrite and sphalerite (Groves and Baker 1972)

b

c

a

0000096 098

Nb

(a

pfu

)

0004

0012

102

0008

W (apfu)

100

000188 192

Nb

5++

Fe

3+ (

apfu

)

004

010

20

008

W6++Fe2++Mn2+ (apfu)

196

002

006

0000

0004

00 0002

Nb+

Ta (

apfu

)

0002

0004

0005

0006 0008

0001

0003

Fe+Mn (apfu)

Cst in veins hosted by equigranular granite

Cst in veins hosted by leucogranite and aplites

wolframite I

wolframite II

Fig 6a ndash Nb + Ta vs Fe + Mn diagram of cassiterite from the intra-granitic quartz veins Variation diagrams for wolframite I and II of the quartz veins hosted by the tourmaline-bearing leucogranite and apical aplites b ndash Nb vs W c ndashNb5+ + Fe3+ vs W6+ + Fe2+ + Mn2+


164

513 Ixiolite

In the triangular diagram (Fig 7a) the ixiolite data are generally observed to be aligned along the (SnTi) ndash (FeMn) 2+(NbTa)2 join suggesting the (FeMn)2+ + 2(NbTa)5+ harr 3(SnTi)4+ mechanism of substitution for the incorporation of these elements into the ixiolite structure (Černyacute et al 1986) However these compo-

sitions deviate slightly from that join in the (SnTi) ndash (FeMn) 3+(NbTa) direction indicating that ixiolite may contain some Fe3+ The fact that the totals of cations normalized to 2 atoms of oxygen do not generally exceed 1 in most of the ixiolite analyses would indicate that the Fe3+ contents are very low (Neiva 1996) Nevertheless the ixiolite composition could also have been controlled by another substitution mechanism as is seen in the

b c

00

00 02

Ti (a

pfu

)

04

10

06

08

Nb+Ta (apfu)

04

02

06

Nb

(a

pfu

)

00

00 01

02

05

04

04

Ta (apfu)

03

01

03

02

rutile I

rutile II

ixiolite

a100

50

100

50

100 50Fe+MnSn+W+Ti

Nb+Ta

Cst Rt

Cl-Tn

(FeMn)3+(NbTa)O4

(FeMn)2+(NbTa)2O6

(FeMn)WO4

Ixl

(SnT

i)

(SnTi)

3(F

eMn)2+ (N

bTa) -2

-1

2(F

eMn)3+ (N

bTa)-4

-1

Fe

W

(NbTa) 4

-1-3

Fig 7a ndash Triangular diagram (Sn + W + Ti) ndash (Nb + Ta) ndash (Fe + Mn) for rutile I and II (Rt) and ixiolite (Ixl) in the intra-granitic mineralized quartz veins showing the dominant substitution mechanism Variation diagrams for rutile and ixiolite b ndash Nb vs Ta c ndash Ti vs Nb + Ta


165

triangular diagram below the data corresponding to the field of the columbite-group minerals (NbTa)4Fendash1Wndash3 (Fig 7a) This suggests that W was incorporated in the ixiolite structure by a wolframite-type substitution The higher the W contents are (exceeding significantly those of Sn) the more pronounced the deviation to the join (NbTa)4Fendash1Wndash3 as described by Suwinonprecha et al (1995) and Neiva (1996)

Furthermore a negative correlation between Nb and Ta can be observed (Fig 7b) although both these elements are partially replaced by Ti (Fig 7c) and W (no shown) Similar compositional variation has been described for the Ti-rich ixiolite exsolutions hosted by cassiterite in quartz veins of the Fental and Muralha deposits Portugal (Neiva 1996)

514 Rutile

The high potential of rutile as a geochemical indicator in many hydrothermal deposits has been attributed to its common presence as accessory mineral and its capacity to accommodate a large variety of substitutions by major and trace elements eg Fe Cr V Nb and Ta (Clark and Williams-Jones 2009) Thus for example rutile associ-ated with granite-related tin deposits typically displays high Sn and W contents whereas that occurring in gra-nitic pegmatites contains Nb and Ta in addition

Oscillatory zoning of the rutile II occurring in the mineralized quartz veins of the Jaacutelama Batholith is in-terpreted as a consequence of variations in Ti concentra-tions due to the variable substitution of Ti by Nb Ta Fe and W In contrast to the ixiolite Nb and Ta show a positive correlation in the rutile I and II samples (Fig 7b) However both ixiolite and rutile display a very good negative correlation between Nb + Ta and Ti (Fig 7c) This would suggest that similar amounts of Nb and Ta entered the rutile structure especially of rutile II to re-place Ti whereby Ta contents are usually slightly higher (Tab 3) The incorporation of Nb Ta and Fe into rutile II corresponds to a Ti3(FeMn) 2+

ndash1(NbTa)ndash2 columbite-type substitution since the rutile data plot along the (SnTi) ndash (FeMn)(NbTa)2 join in the same way as ixiolite and cas-siterite do (Fig 7a) However the variations in charges owing to the presence of Fe2+ and W6+ require a coupled substitution in order to maintain the electro-neutrality This additional substitution might be represented by a 2Ti4+ harr Fe2+ + W6+ vector (Rice et al 1998)

Fluctuations in activity of the components involved (Černyacute et al 2007a) in the crystallization of NbndashTa-rich rutile II have been proposed to have caused the oscil-latory zoning observed in all samples from the Jaacutelama quartz veins Different diffusion rates of Fe Mn Nb and Ta are to be expected along the growth surfaces of the rutile as in other deposits where rutile crystallized

with a similar oscillatory zoning However W does not behave in the same way failing to define oscillatory zoning patterns in rutile (Carruzzo et al 2006 Černyacute et al 2007a) Moreover the low Zr contents in the rutile II support the conclusions by Černyacute et al (2007b) concern-ing the limited possibility of this element to enter the of niobian rutile

The rutile crystals studied in the granites aplites and pegmatite bodies of the Jaacutelama Batholith commonly contain significant Al in their lattice (Llorens and Moro 2012b) As shown in Tab 3 rutile I in the quartz veins of the Salmantina Group was able to accommodate up to 133 wt Al2O3 whereas several samples of rutile II reached even 334 wt Al2O3 The incorporation of Al into the rutile structure was probably compensated by oxygen vacancies through the Al21048576Tindash2Ondash1 substitution mechanism (Hata et al 1996) Even though rutile con-taining up to 9 wt Al2O3 has been synthesized in the laboratory from peraluminous melts (Horng et al 1999) these experiments were not conducted under realistic geo-logic conditions (the parental melt contained Si Al K Ti Nb and Ta but no Fe nor Mn to favor columbite-like sub-stitution as occurs in real geologic environments) The highest Al content so far reported in natural rutile was up to 12 wt Al2O3 (0019 apfu Al) from the highly evolved biotite granite of Podlesiacute (Erzgebirge Czech Republic) and related greisens (Breiter et al 2007) The Podlesiacute rutile however has typically low Nb Ta and Fe contents in contrast to the rutile II from the Jaacutelama quartz veins which accommodate up to 0019 apfu Nb and Ta and up to 0034 apfu Fe

52 Evolution of mineralization in the quartz veins

The evolution of the ore minerals in the quartz veins of the Jaacutelama Batholith is presented on the quadrilateral co-lumbite diagram (Fig 8) in which the data on wolframite I and II rutile I and II and ixiolite are plotted On the one hand wolframite I from the early stage of precipita-tion (mostly ferberite) which is associated with cassit-erite I shows a Ta(Ta + Nb) ratio of 0000ndash0185 and Mn(Mn + Fe) ratio of 0085ndash0604 On the other hand these ratios in wolframite II (huumlbnerite) range between 0000 and 0201 and between 0533 and 0704 respective-ly (Tab 2) According to this the evolutionary trend from the early SnndashW precipitation to the main FendashZn sulphide ore deposition reflects a normal evolution in the quartz veins (from Wf I to Wf II in Fig 8) Likewise taking into account the increasing Fe3+ contents from wolframite I to wolframite II a major contribution of relatively oxidizing waters could be inferred (Williamson et al 2000)

The Sn4+ of the hydrothermal fluid parental quartz veins was fixed in the crystal structure of cassiterite I


166

and II during the early stages of mineralization and the first step of the main ore deposition However during the second step the amount of Sn4+ was probably below the saturation level not permitting the cassiterite crystalliza-tion (Muumlller and Halls 2005) The Sn was incorporated into ixiolite and NbTa-bearing rutile II instead The Ta(Ta + Nb) and Mn(Mn + Fe) ratios in ixiolite vary from 0148 to 0598 and from 0150 to 0365 respectively (Tab 3) thus plotting in intermediate areas of the quadri-lateral diagram (Fig 8) Moreover rutile II shows a broad range of the Ta(Ta + Nb) ratios (0166ndash0770) with low Mn concentrations thus plotting very close to the vertical axis in the columbite diagram (Fig 8)

The hydrothermal evolution of ore minerals in the quartz veins of the Jaacutelama Batholith corresponds to en-richment in Ti and Fe at the expense of Mn from the crystallization of wolframite II to rutile II The strong increase in Fe during the second episode of the main ore deposition indicated by the crystallization of ixiolite and rutile II suggests open-system conditions and an influence of relatively oxidizing fluids (Williamson et al 2000) Thus crystallization of ixiolite and rutile II after wolframite II (Fig 8) represents an inverse evolutionary trend in comparison with the normal Mn and Ta enrich-ment of NbndashTa oxides during melt fractionation (Tindle and Breaks 1998 Beurlen et al 2008) Analogous inverse trend has been described for example from the Quintos pegmatite Borborema Province NE Brazil (Beurlen et al 2008)

However this anomalous evolutionary trend would have not been complete since increasing Ta contents are observed for the crystallization from ixiolite to rutile II

(Fig 8) The high Ti contents of several ixiolite crystals suggest the simultaneous crystallization of ixiolite and ru-tile II at low temperatures (Černyacute et al 1998) Taking into account the lack of replacement textures of ixiolite by rutile II together with the presence of more or less planar growth surfaces between these minerals the oscillatory compositional zoning parallel to the growth surfaces could be considered as a primary texture responding to changes in the mineralizing fluid composition This might be a consequence of the mixing of the hydrothermal fluid with metamorphic andor meteoric fluids enriched in Ti and Fe probably induced by variations in pressure and temperature (Muumlller and Halls 2005) Such fluid contami-nation which is supported by preliminary data on fluid inclusions and stable isotopes in the quartz veins (Llorens 2011) might also have caused the textural variability of rutile II (eg oscillatory zoning patchy textures)

53 Incorporation of Ti Nb and Ta the role of volatiles

The natural development of peraluminous systems as in the case of the Jaacutelama granitic cupola in the Navasfriacuteas district is to evolve towards an enrichment in volatiles such as F Cl andor B due to the fractionation of the melts Thus the residual melts show very low viscosity owing to their high contents of volatiles especially F (Dingwell et al 1985 London 1987 Webster and Hol-loway 1990 Giordano et al 2004) Moreover volatiles have been demonstrated to have a strong influence on the activity of the trace elements present in the melts since

Fig 8 Wolframite ixiolite and rutile mineral data plotted in the columbi-te diagram where two evolutionary trends can be observed (1) a normal trend of Mn-enrichment from wolfra-mite I (Wf I) to wolframite II (Wf II) of the main deposit in the Jaacutelama Batholith quartz veins and (2) a rever-se trend of a Ta- and Fe-enrichment of ixiolite (Ixl) and rutile II (Rt II) of the late deposit

Wf II

Ixl

Rt I

Rt II

Wf I

Main deposit first stage

Main deposit second stage

Early SnndashW deposit

Ta(

Ta+

Nb)

00

00 02

09

08

Mn(Mn+Fe)

0604

05


167

they increase the solubility of the high-field strength ele-ments (Keppler 1993)

Fluorine is a major constituent of the fluids related to Sn-bearing granites (Barsukov and Sushchevskaya 1973 Eadington 1983) playing an important role in the alteration sequence of the original granitic rock According to Pollard (1983) the F enrichment in a Na-rich residual melt such as that which could resulted from the fractional crystallization of the Jaacutelama granitic cupola would have induced a sodium metasomatism during post-magmatic stages in response to increasing pH and aHF The increasing acidity led mainly to the destabilization of potassic feldspar and less so of mica and plagioclase Thus albitization processes could have become widespread along the northern margin of the Jaacutelama Batholith affecting especially the peri-batholithic pegmatite dikes of Cruz del Rayo (Llorens and Moro 2012b) Subsequently greisenization sensu stricto would have promoted the replacement of the minerals form-ing pegmatite dikes with a typical quartz + muscovite assemblage The greisenization processes were caused by an increase in the concentration of volatiles which acidified the environment (Burt 1981) During and after the greisenization silicification processes continued (Pirajno 1992) which could have developed the systems of mineralized quartz veins associated to the granites with mineralization potential the granitic facies of the External Unit (Ruiz et al 2008)

Titanium has been considered to be one of the less mobile elements during hydrothermal processes since it tends to create non-volatile ionic compounds of limited capability of migration through silicate melts when an alteration of magmatic minerals takes place A similar behavior is seen in pure aqueous fluids corroborating the poor mobility of Ti (Ayers and Watson 1993 Audeacutetat and Keppler 2005 Tropper and Manning 2005 Antignano and Manning 2008 Manning et al 2008) However ad-dition of F to the fluid would increase Ti solubility up to 100-fold in comparison with the pure aqueous fluid (Rapp et al 2010) Moreover Na plays an important role in Ti mobility because albite-saturated fluids display high HF contents (Antignano and Manning 2008)

Considering that Ti is a compatible element that is commonly fixed by magmatic minerals two possibili-ties can be proposed to explain its incorporation into the hydrothermal system The first one is the muscovitization of the magmatic minerals containing Ti such as biotite As suggested by Llorens and Moro (2012b) the same process could have played an important role in releasing elements such as Sn Nb and Ta which were fixed in trace amounts in the structures of muscovite and biotite from the granitic facies of the External Unit Muscovitization of biotite would have favored the incorporation of part of the released Ti to rutile and ilmenite whereas the rest

would have escaped to the exsolved fluids responsible for the later mineralization The mobility of Ti up to these late stages of deposition should be favored by Na saturation of the residual melts since the latter show high HF contents (Antignano and Manning 2008) This scheme is in agreement with the conclusions obtained by Fernaacutendez-Leyva (2007) and Ruiz et al (2008) who es-tablished that the granitic facies of the External Unit had high mineralization potential thus favoring the precipi-tation of disseminated Sn- Nb- and Ta-bearing minerals in the granites and the concentration of such elements together with W towards the last hydrothermal fluids to form the mineralized quartz veins

The second possibility invokes a contamination by circulating hydrothermal fluids coming from the host metamorphic rocks This influx of external fluids would not only contribute Ti but also elements such as Mg Ca Sr and Ba (Llorens and Moro 2012a) Bearing in mind that these elements are commonly compatible and thus preferentially incorporated into minerals during the mag-matic stage their presence in the later depositional events may point to a contamination by fluid expelled from the host metamorphic rocks This contamination is also sup-ported by the preliminary data on the fluid inclusions and the stable isotopes studies (Llorens 2011)

In the Jaacutelama Batholith a combination of both pro-cesses muscovitization of biotite and contamination by metamorphic fluids could have promoted the mobiliza-tion of Ti together with other compatible elements and their entry to the structure of cassiterite rutile and ix-iolite This is evident from the early ore deposition where cassiterite I crystallized with high contents in Ti and was associated with Mg- and Ca-bearing phosphates such as triplite (Llorens and Moro 2012a)

The solubility of Ti depends on the chemical composi-tion of the fluids as well as on T and pH The Ti mobility at 400 to 700 degC is higher in F-rich solutions and acid environments since Ti would form complexes with Fndash Clndash and OHndash (Ryzhenko et al 2006) Consequently in a fluid enriched in F and Ti the crystallization of F-bearing minerals will induce the increase in Ti activity and the crystallization of rutile (Rapp et al 2010) In the mineral-ized quartz veins of the Jaacutelama Batholith the presence of F in the ore fluid led to the crystallization of fluorapatite which is present at nearly all the depositional stages in these quartz veins and of isokite which crystallized during the same deposition stage as rutile II and ixiolite (Llorens and Moro 2012a) Both these phosphate miner-als contain high amounts of F

The crystallization of ixiolite with NbndashTa-rich rutile II would suggest a late enrichment in Ti Nb and Ta of the mineralized fluids that formed the intra-granitic quartz veins This could be explained in terms of an increased insolubility of Ta-rich complexes as the F concentration


168

rose in the fluid (Linnen 1998) Consequently Nb and Ta entered into the ixiolite and rutile structure at later crys-tallization stages Moreover Linnen and Keppler (1997) have reported the preference of accessory minerals such as NbndashTa oxides to incorporate more Nb than Ta as it is the case in ixiolite Thus the NbTa ratio progressively de-creased in the residual fluid as the fractionation proceeded

6 Conclusions

The mineralized quartz veins hosted by the distal gra-nitic facies of the Jaacutelama Batholith (Salamanca Spain) resulted from successive processes of fractures opening and their invasion by hydrothermal fluids enriched in volatiles

1 The early ore deposition mainly brought cassiterite I and wolframite I (ferberite) together with subordinate sulphides and rutile I

2 After a ductile deformation and as temperature decreased the main FendashZn sulphide mineralization was deposited from slightly oxidizing fluids followed by smaller quantities of cassiterite II and wolframite II (huumlbnerite)

3 An intense fracturing took place later which al-lowed the introduction of elements into the system For instance Ti presumably came from hydrothermal fluids expelled from the host metamorphic rocks rich in F and P The crystallization of Fe- Mn- Mg- and Ca-bearing phosphates such as isokite and fluorapatite extracted F from the hydrothermal fluid favoring saturation in Ti Nb and Ta This induced the crystallization of ixiolite and NbTa-rich rutile II filling fractures in previous minerals during the second step of the main ore deposition

4 Finally quartz and carbonates filled open spaces and cavities of the quartz veins

Acknowledgements This study was supported by the Co-munidad Autoacutenoma de Castilla y Leoacuten (Research Project Ref SA015A06 and Research Fellowship) Thanks are due to Miguel Aacutengel Fernaacutendez for performing electron-microprobe analyses and providing BSE images and the general assistance during the analytical work The authors gratefully acknowledge M Novaacutek for his editorial han-dling as well as Z Johan and A Lima for their critical reviews and valuable improvements of the manuscript

References

AmichbA Tm DubAkinA LS (1974) ldquoWolframoixioliterdquo in ores of tungsten deposits of Yakutia Sborn Nauchn Trud Mosk Otdel Vses Mineral Obshch 1974 pp 11ndash18 (in Russian)

AnTignAno A mAnning cE (2008) Rutile solubility in H2O H2OndashSiO2 and H2OndashNaAlSi3O8 fluids at 07ndash20 GPa and 700ndash1000 ordmC implications for mobility of nominally insoluble elements Chem Geol 255 283ndash293

AuDeacuteTAT A kEppLEr h (2005) Solubility of rutile in sub-duction zone fluids as determined by experiments in the hydrothermal diamond anvil cell Earth Planet Sci Lett 232 393ndash402

AuriScchio c DE ViTo c FErrini V orLAnDi p (2002) Nb and Ta oxide minerals in the Fonte del Petre granitic pegmatite dike Island of Elba Italy Canad Mineral 40 799ndash814

AyErS Jc WATSon Eb (1993) Rutile solubility and mobility in supercritical aqueous fluids Contrib Mineral Petrol 114 321ndash330

bArSukoV VL SuShchEVSkAyA Tm (1973) On the composi-tion evolution of hydrothermal solutions in the process of the formation of the tin ore deposits Geokhimiya 4 491ndash503 (in Russian)

bEDDoE-STEphEnS b ForTEy nJ (1981) Columbite from the Carrock Fell tungsten deposit Mineral Mag 44 217ndash223

bEurLEn h DA SiLVA mrr ThomAS r SoArES Dr oLiViEr p (2008) NbndashTandash (TindashSn) oxide mineral chemistry as tracer of rare-element granitic pegmatite fractionation in the Borborema Province Northeastern Brazil Miner Depos 43 207ndash228

bonS pD (2000) The formation of veins and their micro-structures In JESSELL mW urAi JL (eds) Stress Strain and Structure ndash A volume in honour of WD Means J Virtual Expl 2 paper 4 doi103809jvirtex200000007

brEiTEr k ŠkoDA r uhEr p (2007) NbndashTandashTindashWndashSnndashox-ide minerals as indicators of peraluminous P- and F-rich granitic system evolution Podlesiacute Czech Republic Mineral Petrol 91 225ndash248

burT Dm (1981) Acidityndashsalinity diagrams Application to greisen and porphyry deposits Econ Geol 76 832ndash843

cArruzzo S cLArkE Db pELrinE km mAcDonALD mA (2006) Texture composition and origin of rutile in the South Mountain Batholith Nova Scotia Canad Mineral 44 715ndash729

cLArk Jr WiLLiAmS-JonES AE (2009) Compositional vari-ability of rutile in hydrothermal ore deposits Am Geo-phys Union Spring Meeting 2009 abstract V14Andash01

Černyacute P ChaPman r (2001) Exsolution and breakdown of scandian and tungstenian NbndashTandashTindashFendashMn phases in niobian rutile Canad Mineral 39 93ndash101

Černyacute P erCit S (1985) Some recent advances in the min-eralogy and geochemistry of Nb and Ta in rare-element granitic pegmatites Bull Mineacuteral 108 499ndash532

Černyacute P erCit S (1989) Mineralogy of niobium and tanta-lum crystal chemical relationships paragenetic aspects and their economic implications In moumlller P Černyacute p SAupeacute F (eds) Lanthanides Tantalum and Niobium


169

SGA Special Publications 7 Springer-Verlag New York pp 27ndash29

Černyacute P erCit tS (2005) The classification of granitic pegmatites revisited Canad Mineral 43 2005ndash2026

Černyacute P meintzer re anderSon aJ (1985) Extreme fraction-ation in rare-element granitic pegmatites selected examples of data and mechanism Canad Mineral 23 381ndash421

Černyacute P Goad Be hawthorne C ChaPman r (1986) Fractionation trends of the Nb- and Ta-bearing oxide minerals in the Greer Lake pegmatitic granite and its pegmatite aureole southeastern Manitoba Amer Miner 71 501ndash517

Černyacute P erCit tS wiSe ma ChaPman r BuCk m (1998) Compositional structural and phase relationships in titanian ixiolite and titanian columbitendashtantalite Canad Mineral 36 574ndash561

Černyacute P novaacutek m ChaPman r Ferreira k (2007a) Sub-solidus behavior of niobian rutile from the Piacutesek region Czech Republic a model for exsolution in W- and Fe2+ gtgt Fe3+-rich phases J Geosci 52 143ndash159

Černyacute P erCit tS SmedS S-a Groat la ChaPman r (2007b) Zirconium and hafnium in minerals of the co-lumbite and wodginite groups from granitic pegmatites Canad Mineral 45 185ndash202

DingWELL Db ScArFE cm cronin DJ (1985) The effect of fluorine on the viscosities of melts in the system Na2OndashAl2O3ndashSiO2 implications for phonolites trachytes and rhyolites Amer Miner 7080ndash87

EADingTon pJ (1983) A fluid inclusion investigation of ore formation in a tin-mineralized granite New England New South Wales Econ Geol 78 1204ndash1221

erCit tS Černyacute P hawthorne FC mCCammon Ca (1992) The wodginite group II Crystal chemistry Canad Min-eral 30 613ndash631

Fernaacutendez-leyva C (2007) Metallogenetic Study of the Jaacutelama Batholith and Surroundings Unpublished PhD thesis Universidad Politeacutectnica de Madrid Madrid pp 1ndash188 (in Spanish)

giorDAno D romAno c poE b DingWELL Db bEhrEnS h (2004) The combined effects of waacuteter and fluorine on the viscosity of silicic magmas Geochim Cosmochim Acta 68 5159ndash5168

giuLiAni g (1987) La cassiteacuterite zone du gisement de Sokhret Allal (Granite des Zaeumlr Maroc Central) com-position chimique et phases fluides associeacutees Miner Depos 22 253ndash261

gouAnVic y bAbkinE J (1985) Metallogenie du gisement agrave tunstegravene-etain de Monteneme (NW Galice Espagne) Miner Depos 20 8ndash15

groVES DJ bAkEr WE (1972) The regional variation in composition of wolframites from Tasmania Econ Geol 67 362ndash368

hAApALA i (1997) Magmatic and postmagmatic processes in tin-mineralized granites topaz-bearing leucogranite in

the Eurajoki Rapakivi Granite Stock Finland J Petrol 38 1645ndash1659

hATA k higuchi m TAkAhAShi J koDAirA k (1996) Float-ing zone growth and characterization of aluminium-doped rutile single crystals J Cryst Growth 163 279ndash284

horng W-S hESS pc gAn h (1999) The interaction be-tween M+5 cations (Nb+5 Ta+5 or P+5) and anhydrous haplogranite melts Geochim Cosmochim Acta 63 2419ndash2428

JohAn V JohAn z (1994) Accessory minerals of the Ciacutenovec (Zinnwald) granite cupola Czech Republic Part 1 Nb- Ta- and Ti-bearing oxides Mineral Petrol 51 323ndash343

kEppLEr h (1993) Influence of fluorine on the enrichment of high field strength trace elements in granitic rocks Contrib Mineral Petrol 114 479ndash488

LErougE c DESchAmpS y piAnTonE p giLLES c brETon J (2007) Metal-carrier accessory minerals associated with W plusmn Sn mineralization La Chacirctaigneraie tungsten ore district Massif Central France Canad Mineral 45 875ndash889

LinnEn rL (1998) The solubility of NbndashTandashZrndashHfndashW in granitic melts with Li and Li + F constraints for min-eralization in rare metal granites and pegmatites Econ Geol 93 1013ndash1025

LinnEn rL kEppLEr h (1997) Columbite stability in granitic melts consequences for the enrichment and fractionation of Nb and Ta in the Earth crust Contrib Mineral Petrol 128 213ndash227

LLorEnS T (2011) The SnndashWndash(NbndashTa) MagmaticndashHydro-thermal Mineralizations of the Navasfriacuteas District (SW Salamanca) PhD thesis Salamanca University Viacutetor Collection 290 pp 1ndash353 ISBN 978-84-7800-088-3 (in Spanish)

LLorEnS T moro mc (2007) Preliminary study of intragra-nitic pegmatites in the SnndashWndash (Au) district of Navasfriacuteas (SW of Salamanca Spain) In mArTinS T ViEirA r (eds) Granitic Pegmatites the State of the Art Book of Ab-stracts Universidad do Porto Department of Geology Porto Memoacuterias 8 56ndash57

LLorEnS T moro mc (2008) AlndashFendashMn phosphates in the intra-granitic pegmatites of the Navasfriacuteas district (SW Salamanca) In DELgADo J ASTiLLEroS Jm bAuLuz b Calvo B Gonzaacutelez i herrero Jm loacutePez J Proenza J roDriacuteguEz c (eds) XXVIII Reunioacuten de la Sociedad Espantildeola de Mineralogiacutea XXI Reunioacuten de la Sociedad Espantildeola de Arcillas Sociedad Espantildeola de Mineralogiacutea Macla 9 145ndash146 (in Spanish)

LLorEnS T moro mc (2010a) Microlite and tantalite in the LCT granitic pegmatites of La Canalita Navasfriacuteas SnndashW District Salamanca Spain Canad Mineral 48 549ndash564

LLorEnS T moro mc (2010b) Columbite-group minerals in the Cruz del Rayo pegmatite dikes SW Salamanca Spain In Paacutel-molnaacuter e aacuterkai P Buda G doacutedony i


170

FAncSik T FoumlLDESSy J hArAngi S hETeacutenyi m koroknAi B toacuteth tm PaPP G PoacuteSFai m roacutezSa P SiPoS P SzaBoacute C Szakaacutell S Szederkeacutenyi t viCziaacuten i zelenka t (eds) IMA 2010 Bonds and Bridges CD of Abstracts Department of Mineralogy Geochemistry and Petrology University of Szeged Acta Mineral Petrogr Abstr Ser Szeged 6 167

LLorEnS T moro mc (2010c) NbndashTa-oxide minerals in the LCT pegmatites of La Canalita SW Salamanca Spain In Paacutel-molnaacuter e aacuterkai P Buda G doacutedony i FanC-Sik T FoumlLDESSy J hArAngi S hETeacutenyi m koroknAi b toacuteth tm PaPP G PoacuteSFai m roacutezSa P SiPoS P SzaBoacute C Szakaacutell S Szederkeacutenyi t viCziaacuten i zelenka t (eds) IMA 2010 Bons and Bridges CD of Abstracts Budapest Department of Mineralogy Geochemistry and Petrology University of Szeged Acta Mineral Petrogr Abstr Ser Szeged 6 167

LLorEnS T moro mc (2012a) FendashMn phosphate associa-tions as indicators of the magmaticndashhydrothermal and supergene evolution of the Jaacutelama Batholith in the Navasfriacuteas SnndashW District Salamanca Spain Mineral Mag 76 1ndash24

LLorEnS T moro mc (2012b) Oxide minerals in the granitic cupola of the Jaacutelama Batholith Salamanca Spain Part I accessory Sn Nb Ta and Ti minerals in leucogranites aplites and pegmatites J Geosci 57 25ndash43

LonDon D (1987) Internal differentiation of rare-element pegmatites effects on boron phosphorus and fluorine Geochim Cosmochim Acta 51 403ndash420

mAnning cE WiLkE m SchmiDT c cAuziD J (2008) Rutile solubility in albitendashH2O and Na2Si3O7ndashH2O at high tem-peratures and pressures by in-situ synchrotron radiation micro-XRF Earth Planet Sci Lett 272 730ndash737

martiacutenez Catalaacuten Jr martiacutenez PoyatoS d Bea F (2004) Centro-Iberic Zone In VErA JA (ed) Geology of Spain SGEndashIGME Madrid pp 68ndash133 (in Spanish)

mArTinS T LimA A SimmonS S FALSTEr A noronhA F (2011) Geochemical fractionation of NbndashTa oxides in Li-bearing pegmatites from the BarrosondashAlvatildeo pegmatite field Northern Portugal Canad Mineral 49 777ndash791

moumlLLEr p DuLSki p SzAcki W mALoW g riEDEL E (1988) Substitution of tin in cassiterite by tantalum niobium tungsten iron and manganese Geochim Cosmochim Acta 52 1497ndash1503

moro mc LLorEnS T (2008) Triplitendashapatitendashisokite in the SnndashW intragranitic quartz veins of La Salmantina (Navasfriacuteas SW Salamanca) In DELgADo J ASTiLLEroS Jm Bauluz B Calvo B Gonzaacutelez i herrero Jm loacutePez J proEnzA J roDriacuteguEz c (eds) XXVIII Reunioacuten de la Sociedad Espantildeola de Mineralogiacutea XXI Reunioacuten de la Sociedad Espantildeola de Arcillas Sociedad Espantildeola de Mineralogiacutea Macla 9 167ndash168 (in Spanish)

moro mC villar P Fadoacuten o Fernaacutendez a CemBranoS mL crESpo JL (2001) Bismuthinite pavonite gustavite

and lillianite homologues in the SnndashW deposits of the Navasfriacuteas district (SW Salamanca) Bol Soc Esp Mineral 24ndashA 161ndash162 (abstract in Spanish)

muumlLLEr A hALLS c (2005) Rutile ndash the tinndashtungsten host in the intrusive tourmaline breccia at Wheal Remfry SW England In mAo J biErLEin Fp (eds) Mineral Deposit Research Meeting the Global Challenge Pro-ceedings of the Eighth Biennial SGA Meeting Beijing pp 441ndash444

nEiVA Amr (1996) Geochemistry of cassiterite and its in-clusions and exsolution products from tin and tungsten deposits in Portugal Canad Mineral 34 745ndash768

nEiVA Amr (2008) Geochemistry of cassiterite and wol-framite from tin and tungsten quartz veins in Portugal Ore Geol Rev 33 221ndash238

novaacutek m Johan z Škoda r Černyacute P Šrein v veSelovSkyacute F (2008) Primary oxide minerals in the system WO3ndashNb2O5ndashTiO2ndashFe2O3ndashFeO and their breakdown products from the pegmatite No 3 at Dolniacute BoryndashHatě Czech Republic Eur J Mineral 20 487ndash499

pAL Dc miShrA b bErnhArDT h-J (2007) Mineralogy and geochemistry of pegmatite-hosted Sn- TandashNb- and ZrndashHf-bearing minerals from the southeastern part of the BastarndashMalkangiri pegmatite belt Central India Ore Geol Rev 30 30ndash55

pirAJno F (1992) Hydrothermal mineral deposits Principles and Fundamental Concepts for the Exploration Geologist Springer-Verlag Heidelberg pp 1ndash710

poLLArD pJ (1983) Magmatic and postmagmatic processes in the formation of rocks associated with rare-element deposits Trans Inst Min Metall 92 B1ndashB9

poLyA DA (1988) Compositional variation in wolframites from the Barroca Grande mine Portugal evidence for fault-controlled ore formation Mineral Mag 52 497ndash503

rAmiacuterEz JA (1996) Petrological Geochemical and Isotopic Study of the Jaacutelama Batholith (North of Extremadura) Unpublished PhD thesis University of Granada pp 1ndash201 (in Spanish)

rAmiacuterEz JA grunDVig S (2000) Causes of geochemical diversity in peraluminous granitic plutons the Jaacutelama Pluton Central-Iberian Zone (Spain and Portugal) Lithos 50 171ndash190

rApp JF kLEmmE S buTLEr ib hArLEy SL (2010) Extreme-ly high solubility of rutile in chloride and fluoride-bearing metamorphic fluids an experimental investigation Geol-ogy 38 323ndash326

rEneacute m ŠkoDA r (2011) NbndashTandashTi oxides fractionation in rare-metal granites KraacutesnondashHorniacute Slavkov ore district Czech Republic Mineral Petrol 103 37ndash48

ricE cm DArkE kE STiLL JW (1998) Tungsten-bearing rutile from the Kori Kollo gold mine Bolivia Mineral Mag 62 421ndash429

ruiz C Fernaacutendez-leyva C loCutura J (2008) Geochem-istry geochronology and mineralisation potential of the


171

granites in the Central Iberian Zone the Jaacutelama Batholith Chem Erde 68 413ndash429

ryzhEnko b koVALEnko n priSyAginA n (2006) Titanium complexation in hydrothermal systems Geochem Int 44 879ndash895

SpiLDE mn ShEArEr ck (1992) A comparison of tanta-lumndashniobium oxide assemblages in two mineralogically distinct rare-element granitic pegmatites Black Hills South Dakota Canad Mineral 30 719ndash737

SuwinonPreCha P Černyacute P FriedriCh G (1995) Rare metal mineralization related to granites and pegmatites Phuket Thailand Econ Geol 90 603ndash615

TinDLE Ag brEAkS FW (1998) Oxide minerals of the Separation Rapids rare-element granitic pegmatite group northwestern Ontario Canad Mineral 36 609ndash635

TinDLE Ag WEbb pc (1989) Niobian wolframite from Glen Gairn in the eastern Highlands of Scotland a mi-croprobe investigation Geochim Cosmochim Acta 53 1921ndash1935

TinDLE Ag brEAkS FW WEbb pc (1998) Wodginite-group minerals from the Separation Rapids rare-element gra-nitic pegmatite group northwestern Ontario Canad Mineral 36 637ndash658

TroppEr p mAnning cE (2005) Very low solubility of rutile in H2O at high pressure and temperature and its implications for Ti mobility in subduction zones Amer Miner 90 502ndash505

WEbSTEr JD hoLLoWAy Jr (1990) Partitioning of F and Cl between magmatic hydrothermal fluids and highly evolved granitic magmas In STEin hJ hAnnAh JL (eds) Ore-Bearing Granite Systems Petrogenesis and Mineral-izing Processes Geological Society of America Special Papers 246 21ndash34

WiLLiAmSon bJ SprATT J ADAmS JT TinDLE Ag STAnLEy cJ (2000) Geochemical constraints from zoned hydrother-mal tourmalines on fluid evolution and Sn mineralization an example from fault breccias at Roche SW England J Petrol 41 1439ndash1453


156

facies and the pegmatite dikes Thus the main objectives are 1) to identify the different episodes of mineralization in the quartz veins 2) to characterize texturally miner-alogically and chemically SnndashWndashNbndashTandashTi minerals of each episode 3) to describe the substitution mechanisms and zoning patterns of these minerals 4) to define the chemical evolution of the SnndashWndashNbndashTandashTi minerals in the quartz veins through their textural relationships and compositional variations and finally 5) to determine the role of volatiles in the formation of this deposit

2 Geological setting

The Jaacutelama Batholith intruded the pre-Ordovician grey-wackendashpelite metasediments of the Schist-Greywacke Complex Domain (CEG) in the middlendashwestern Iberian Peninsula (Martiacutenez Catalaacuten et al 2004) after the main Variscan deformational phases (~300 Ma Ramiacuterez 1996) The External Unit of the Jaacutelama Batholith (Ramiacuterez 1996 Ramiacuterez and Grundvig 2000) hosts the main tinndashtungsten deposits of the Navasfriacuteas district (geographic coordinates



Jaacutelama

Batholith

Jaacutelama

Batholith

Guarda Batholith

Spain

0 3 km

Salmantina Group

External Unit

Salamanca

Tertiary

Granites

Paleozoic

Gradual contact Intrusive contact

Fractures Qtz veins directions

Tourmaline-bearing leucogranite

Apical aplitesTwo-mica granite

SchistndashGraywacke Complex (CEG)Porphyritic monzogranite

CEG

Horia amp Mari Carmen

Bon

N

Iberian Massif

0 20 km

SnndashW deposit

Portugal Spain

Sn depositSn depositNavasfriacuteasNavasfriacuteas

SnndashW deposit

3 km

Fig 1 Location of the Jaacutelama Batholith in the Navasfriacuteas SnndashW district (central part of the Iberian Massif) The principal directions of the mine-ralized quartz veins that were mined can be seen Based on Ramiacuterez (1996)


157










158






41 Cassiterite



FendashCu sulphides

Cassiterite

Wolframite

Rutile


FendashZn sulphides

Ixiolite




159



42 Wolframite






160


43 Ixiolite



44 Rutile









161






162



5 Discussion






163


511 Cassiterite



512 Wolframite




b

c

a

0000096 098

Nb

(a

pfu

)

0004

0012

102

0008

W (apfu)

100

000188 192

Nb

5++

Fe

3+ (

apfu

)

004

010

20

008


196

002

006

0000

0004

00 0002

Nb+

Ta (

apfu

)

0002

0004

0005

0006 0008

0001

0003

Fe+Mn (apfu)



wolframite I

wolframite II



164

513 Ixiolite



b c

00

00 02

Ti (a

pfu

)

04

10

06

08

Nb+Ta (apfu)

04

02

06

Nb

(a

pfu

)

00

00 01

02

05

04

04

Ta (apfu)

03

01

03

02

rutile I

rutile II

ixiolite

a100

50

100

50

100 50Fe+MnSn+W+Ti

Nb+Ta

Cst Rt

Cl-Tn

(FeMn)3+(NbTa)O4

(FeMn)2+(NbTa)2O6

(FeMn)WO4

Ixl

(SnT

i)

(SnTi)

3(F

eMn)2+ (N

bTa) -2

-1

2(F

eMn)3+ (N

bTa)-4

-1

Fe

W

(NbTa) 4

-1-3



165



514 Rutile











166








Wf II

Ixl

Rt I

Rt II

Wf I




Ta(

Ta+

Nb)

00

00 02

09

08

Mn(Mn+Fe)

0604

05


167











168


6 Conclusions







References


















169































170




























171












157










158






41 Cassiterite



FendashCu sulphides

Cassiterite

Wolframite

Rutile


FendashZn sulphides

Ixiolite




159



42 Wolframite






160


43 Ixiolite



44 Rutile









161






162



5 Discussion






163


511 Cassiterite



512 Wolframite




b

c

a

0000096 098

Nb

(a

pfu

)

0004

0012

102

0008

W (apfu)

100

000188 192

Nb

5++

Fe

3+ (

apfu

)

004

010

20

008


196

002

006

0000

0004

00 0002

Nb+

Ta (

apfu

)

0002

0004

0005

0006 0008

0001

0003

Fe+Mn (apfu)



wolframite I

wolframite II



164

513 Ixiolite



b c

00

00 02

Ti (a

pfu

)

04

10

06

08

Nb+Ta (apfu)

04

02

06

Nb

(a

pfu

)

00

00 01

02

05

04

04

Ta (apfu)

03

01

03

02

rutile I

rutile II

ixiolite

a100

50

100

50

100 50Fe+MnSn+W+Ti

Nb+Ta

Cst Rt

Cl-Tn

(FeMn)3+(NbTa)O4

(FeMn)2+(NbTa)2O6

(FeMn)WO4

Ixl

(SnT

i)

(SnTi)

3(F

eMn)2+ (N

bTa) -2

-1

2(F

eMn)3+ (N

bTa)-4

-1

Fe

W

(NbTa) 4

-1-3



165



514 Rutile











166








Wf II

Ixl

Rt I

Rt II

Wf I




Ta(

Ta+

Nb)

00

00 02

09

08

Mn(Mn+Fe)

0604

05


167











168


6 Conclusions







References


















169































170




























171












158






41 Cassiterite



FendashCu sulphides

Cassiterite

Wolframite

Rutile


FendashZn sulphides

Ixiolite




159



42 Wolframite






160


43 Ixiolite



44 Rutile









161






162



5 Discussion






163


511 Cassiterite



512 Wolframite




b

c

a

0000096 098

Nb

(a

pfu

)

0004

0012

102

0008

W (apfu)

100

000188 192

Nb

5++

Fe

3+ (

apfu

)

004

010

20

008


196

002

006

0000

0004

00 0002

Nb+

Ta (

apfu

)

0002

0004

0005

0006 0008

0001

0003

Fe+Mn (apfu)



wolframite I

wolframite II



164

513 Ixiolite



b c

00

00 02

Ti (a

pfu

)

04

10

06

08

Nb+Ta (apfu)

04

02

06

Nb

(a

pfu

)

00

00 01

02

05

04

04

Ta (apfu)

03

01

03

02

rutile I

rutile II

ixiolite

a100

50

100

50

100 50Fe+MnSn+W+Ti

Nb+Ta

Cst Rt

Cl-Tn

(FeMn)3+(NbTa)O4

(FeMn)2+(NbTa)2O6

(FeMn)WO4

Ixl

(SnT

i)

(SnTi)

3(F

eMn)2+ (N

bTa) -2

-1

2(F

eMn)3+ (N

bTa)-4

-1

Fe

W

(NbTa) 4

-1-3



165



514 Rutile











166








Wf II

Ixl

Rt I

Rt II

Wf I




Ta(

Ta+

Nb)

00

00 02

09

08

Mn(Mn+Fe)

0604

05


167











168


6 Conclusions







References


















169































170




























171












159



42 Wolframite






160


43 Ixiolite



44 Rutile









161






162



5 Discussion






163


511 Cassiterite



512 Wolframite




b

c

a

0000096 098

Nb

(a

pfu

)

0004

0012

102

0008

W (apfu)

100

000188 192

Nb

5++

Fe

3+ (

apfu

)

004

010

20

008


196

002

006

0000

0004

00 0002

Nb+

Ta (

apfu

)

0002

0004

0005

0006 0008

0001

0003

Fe+Mn (apfu)



wolframite I

wolframite II



164

513 Ixiolite



b c

00

00 02

Ti (a

pfu

)

04

10

06

08

Nb+Ta (apfu)

04

02

06

Nb

(a

pfu

)

00

00 01

02

05

04

04

Ta (apfu)

03

01

03

02

rutile I

rutile II

ixiolite

a100

50

100

50

100 50Fe+MnSn+W+Ti

Nb+Ta

Cst Rt

Cl-Tn

(FeMn)3+(NbTa)O4

(FeMn)2+(NbTa)2O6

(FeMn)WO4

Ixl

(SnT

i)

(SnTi)

3(F

eMn)2+ (N

bTa) -2

-1

2(F

eMn)3+ (N

bTa)-4

-1

Fe

W

(NbTa) 4

-1-3



165



514 Rutile











166








Wf II

Ixl

Rt I

Rt II

Wf I




Ta(

Ta+

Nb)

00

00 02

09

08

Mn(Mn+Fe)

0604

05


167











168


6 Conclusions







References


















169































170




























171












160


43 Ixiolite



44 Rutile









161






162



5 Discussion






163


511 Cassiterite



512 Wolframite




b

c

a

0000096 098

Nb

(a

pfu

)

0004

0012

102

0008

W (apfu)

100

000188 192

Nb

5++

Fe

3+ (

apfu

)

004

010

20

008


196

002

006

0000

0004

00 0002

Nb+

Ta (

apfu

)

0002

0004

0005

0006 0008

0001

0003

Fe+Mn (apfu)



wolframite I

wolframite II



164

513 Ixiolite



b c

00

00 02

Ti (a

pfu

)

04

10

06

08

Nb+Ta (apfu)

04

02

06

Nb

(a

pfu

)

00

00 01

02

05

04

04

Ta (apfu)

03

01

03

02

rutile I

rutile II

ixiolite

a100

50

100

50

100 50Fe+MnSn+W+Ti

Nb+Ta

Cst Rt

Cl-Tn

(FeMn)3+(NbTa)O4

(FeMn)2+(NbTa)2O6

(FeMn)WO4

Ixl

(SnT

i)

(SnTi)

3(F

eMn)2+ (N

bTa) -2

-1

2(F

eMn)3+ (N

bTa)-4

-1

Fe

W

(NbTa) 4

-1-3



165



514 Rutile











166








Wf II

Ixl

Rt I

Rt II

Wf I




Ta(

Ta+

Nb)

00

00 02

09

08

Mn(Mn+Fe)

0604

05


167











168


6 Conclusions







References


















169































170




























171












161






162



5 Discussion






163


511 Cassiterite



512 Wolframite




b

c

a

0000096 098

Nb

(a

pfu

)

0004

0012

102

0008

W (apfu)

100

000188 192

Nb

5++

Fe

3+ (

apfu

)

004

010

20

008


196

002

006

0000

0004

00 0002

Nb+

Ta (

apfu

)

0002

0004

0005

0006 0008

0001

0003

Fe+Mn (apfu)



wolframite I

wolframite II



164

513 Ixiolite



b c

00

00 02

Ti (a

pfu

)

04

10

06

08

Nb+Ta (apfu)

04

02

06

Nb

(a

pfu

)

00

00 01

02

05

04

04

Ta (apfu)

03

01

03

02

rutile I

rutile II

ixiolite

a100

50

100

50

100 50Fe+MnSn+W+Ti

Nb+Ta

Cst Rt

Cl-Tn

(FeMn)3+(NbTa)O4

(FeMn)2+(NbTa)2O6

(FeMn)WO4

Ixl

(SnT

i)

(SnTi)

3(F

eMn)2+ (N

bTa) -2

-1

2(F

eMn)3+ (N

bTa)-4

-1

Fe

W

(NbTa) 4

-1-3



165



514 Rutile











166








Wf II

Ixl

Rt I

Rt II

Wf I




Ta(

Ta+

Nb)

00

00 02

09

08

Mn(Mn+Fe)

0604

05


167











168


6 Conclusions







References


















169































170




























171












162



5 Discussion






163


511 Cassiterite



512 Wolframite




b

c

a

0000096 098

Nb

(a

pfu

)

0004

0012

102

0008

W (apfu)

100

000188 192

Nb

5++

Fe

3+ (

apfu

)

004

010

20

008


196

002

006

0000

0004

00 0002

Nb+

Ta (

apfu

)

0002

0004

0005

0006 0008

0001

0003

Fe+Mn (apfu)



wolframite I

wolframite II



164

513 Ixiolite



b c

00

00 02

Ti (a

pfu

)

04

10

06

08

Nb+Ta (apfu)

04

02

06

Nb

(a

pfu

)

00

00 01

02

05

04

04

Ta (apfu)

03

01

03

02

rutile I

rutile II

ixiolite

a100

50

100

50

100 50Fe+MnSn+W+Ti

Nb+Ta

Cst Rt

Cl-Tn

(FeMn)3+(NbTa)O4

(FeMn)2+(NbTa)2O6

(FeMn)WO4

Ixl

(SnT

i)

(SnTi)

3(F

eMn)2+ (N

bTa) -2

-1

2(F

eMn)3+ (N

bTa)-4

-1

Fe

W

(NbTa) 4

-1-3



165



514 Rutile











166








Wf II

Ixl

Rt I

Rt II

Wf I




Ta(

Ta+

Nb)

00

00 02

09

08

Mn(Mn+Fe)

0604

05


167











168


6 Conclusions







References


















169































170




























171












163


511 Cassiterite



512 Wolframite




b

c

a

0000096 098

Nb

(a

pfu

)

0004

0012

102

0008

W (apfu)

100

000188 192

Nb

5++

Fe

3+ (

apfu

)

004

010

20

008


196

002

006

0000

0004

00 0002

Nb+

Ta (

apfu

)

0002

0004

0005

0006 0008

0001

0003

Fe+Mn (apfu)



wolframite I

wolframite II



164

513 Ixiolite



b c

00

00 02

Ti (a

pfu

)

04

10

06

08

Nb+Ta (apfu)

04

02

06

Nb

(a

pfu

)

00

00 01

02

05

04

04

Ta (apfu)

03

01

03

02

rutile I

rutile II

ixiolite

a100

50

100

50

100 50Fe+MnSn+W+Ti

Nb+Ta

Cst Rt

Cl-Tn

(FeMn)3+(NbTa)O4

(FeMn)2+(NbTa)2O6

(FeMn)WO4

Ixl

(SnT

i)

(SnTi)

3(F

eMn)2+ (N

bTa) -2

-1

2(F

eMn)3+ (N

bTa)-4

-1

Fe

W

(NbTa) 4

-1-3



165



514 Rutile











166








Wf II

Ixl

Rt I

Rt II

Wf I




Ta(

Ta+

Nb)

00

00 02

09

08

Mn(Mn+Fe)

0604

05


167











168


6 Conclusions







References


















169































170




























171












164

513 Ixiolite



b c

00

00 02

Ti (a

pfu

)

04

10

06

08

Nb+Ta (apfu)

04

02

06

Nb

(a

pfu

)

00

00 01

02

05

04

04

Ta (apfu)

03

01

03

02

rutile I

rutile II

ixiolite

a100

50

100

50

100 50Fe+MnSn+W+Ti

Nb+Ta

Cst Rt

Cl-Tn

(FeMn)3+(NbTa)O4

(FeMn)2+(NbTa)2O6

(FeMn)WO4

Ixl

(SnT

i)

(SnTi)

3(F

eMn)2+ (N

bTa) -2

-1

2(F

eMn)3+ (N

bTa)-4

-1

Fe

W

(NbTa) 4

-1-3



165



514 Rutile











166








Wf II

Ixl

Rt I

Rt II

Wf I




Ta(

Ta+

Nb)

00

00 02

09

08

Mn(Mn+Fe)

0604

05


167











168


6 Conclusions







References


















169































170




























171












165



514 Rutile











166








Wf II

Ixl

Rt I

Rt II

Wf I




Ta(

Ta+

Nb)

00

00 02

09

08

Mn(Mn+Fe)

0604

05


167











168


6 Conclusions







References


















169































170




























171












166








Wf II

Ixl

Rt I

Rt II

Wf I




Ta(

Ta+

Nb)

00

00 02

09

08

Mn(Mn+Fe)

0604

05


167











168


6 Conclusions







References


















169































170




























171












167











168


6 Conclusions







References


















169































170




























171












168


6 Conclusions







References


















169































170




























171












169































170




























171












170




























171












171











original paper oxide minerals in the granitic cupola …salamanca, spain. part ii: sn, w and ti...

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